The purpose of this project will be to evaluate the influence of recently identified polymorphisms of the hepatic lipase gene on plasma HDL levels, on lipoprotein metabolism, and on risk for CHD. In addition we will seek for new polymorphisms in the hepatic lipase gene for which in vivo and in vitro expression studies can be carried out. The proposed studies should contribute to our understanding of the genetic regulation of hepatic lipase and the functional significance of this enzyme.